The biggest problem is that there is no one providing a guarantee of one device's compatability with the FW protocol as compared to another. So no matter how good the Apple built-in controller is, you are going to get crap happening depending on the devices connected to it. Jeff is correct, FireWire was specified so that devices can run at different speeds (an advantage over USB) and should not be a problem... at least in theory. In the end, whether you daisy chain or use different ports, you are still using one controller so that there are more collisions and less efficiency (but again, this should still work fine for what you are doing).

You could drop $50 and get a PCI FW card... but most likely the problem is the 2MB buffer on the drive. Can you borrow another drive and see if it works better? Have you tried running both on the FW 400 ports?

I would try different ports and configurations, as Mark suggests, as a means of determining if your drive will be usable. The small buffer certainly could be part of the problem. Have you talked to the LaCie support yet? In the past they have been very helpful and seem well versed on Mac issues. Have you looked on their site for new drivers or firmware revisions?

ive given up for now. im just going to log to an internal and move it afterwards. so silly... i now have an issue with batch capturing. im willing to bet its xl1 related, and im going to do a search on it now.

Once you have tried connecting the camera to the rear ports, and if that does not change your situation, can you bypass the external HD altogether (make your internal the scratch disk) are you able to capture properly? This would be a test.